More than sixty years ago, Paul A. Bigsby invented a device which allows a musician to modify the pitch of an electric guitar while it was being played (see, for example, U.S. Pat. Nos. Des. 169,120 and 170,109). Variations of such devices are now commonly referred to as whammy bars, vibrato bars or (incorrectly) tremolo arms. By pushing down or pulling up on the arm of the device, a musician can lower or raise the tension in the guitar strings and the resulting pitch of the note/chord being played on the guitar.
The design of a Bigsby vibrato device has changed little over the years. A typical Bigsby vibrato device is illustrated in FIG. 1. The Bigsby device 10 is configured for installation on the top of the body of a guitar (not illustrated), and it includes a rotatable rod or bar 12 to which the guitar strings (not illustrated) are terminated at the bridge end of the guitar. A spring-loaded arm 14 is attached to the rod 12 so that movement of the arm 14 causes rotation of the rod 12 about its longitudinal axis A-A. Attachment of the arm 14 to the device 10 may allow rotation of the arm 14 about a vertical axis (directional notations herein assume that the vibrato device, or guitar to which it is attached, is laying on a horizontal surface with the guitar strings upward). Tension in the strings imposes a rotational force on the rod 12 which is balanced by the force of the spring 16 located under the arm 14. Movement of the arm 14 downward by a user of the device causes rotation of the rod 12 in a direction which decreases the tension in the strings to lower the pitch, and movement of the arm 14 upward by the user increases the tension in the strings to raise the pitch.
One disadvantage of a Bigsby vibrato device is that the arm/rod does not always return to exactly the same neutral/rest position when released due to mechanical tolerances and friction in the Bigsby device or guitar. Movement at either terminus of a guitar string will affect the tension in the string, and an error of as little as a thousandth of an inch in the neutral return position of the Bigsby device can change the pitch of a string by as much as one-half full tone. Thus, the use of a Bigsby device necessitates frequent tuning of a guitar, and can even cause mistuning of the guitar during the playing of a single song.
Competing vibrato device designs have been introduced over the years in an attempt to address the Bigsby mistuning issue and to provide a larger range of tone change than is provided by a Bigsby device. Floyd D. Rose was awarded U.S. Pat. No. 4,171,661 in 1979 for a competing device called a Floyd Rose Tremolo, and he was awarded U.S. Pat. No. 4,497,236 in 1985 for a fine tuning device which can be used in conjunction with the Floyd Rose device. However, many musicians still prefer the tonal quality and feel of the original Bigsby vibrato device. Yet, tone stability when using a Bigsby device remains problematic, as may be evidenced by searching “Bigsby tuning” on the popular internet site youtube.com. Thus, a solution to the mistuning caused by a Bigsby vibrato device remains a long felt need.
Like structures shown in multiple figures are generally numbered consistently when illustrated in multiple figures.